
public class string16 {

	public static void main(String[] args)throws Exception
	{
		String str1 = "aaaaa", str2 = "bbbbb";
		int posNum = 2;
		StringBuilder strb = new StringBuilder(str1);
		str1 = strb.insert(posNum, str2).toString();
		System.out.println(str1);
	}

}
